Polyol blends and their use in producing PUR-PIR foam-forming compositions

Abstract

Polyol blends are disclosed that include a saccharide-initiated polyether polyol, an aromatic polyester polyol, and a polyalkylene polyamine-initiated polyether polyol. Also disclosed are foam-forming compositions containing such polyol blends, rigid foams made using such polyurethane foam-forming compositions, and methods for producing such foams, including use of such foams as panel insulation.

What is claimed is: 
     
       1. A polyol blend comprising:
 (a) a saccharide-initiated polyether polyol having an OH number of 200 to 600 mg KOH/g and a functionality of 4 to 6; 
 (b) an aromatic polyester polyol having an OH number of 150 to 410 mg KOH/g and a functionality of 1.5 to 3; and 
 (c) a polyalkylene polyamine-initiated polyether polyol having a functionality of 3 to 8 and an OH number of at least 150 mg KOH/g, wherein 
 the polyalkylene polyamine-initiated polyether polyol is present in an amount of 5 to 40% by weight, based on the total weight of the polyol blend. 
 
     
     
       2. The polyol blend of  claim 1 , wherein the saccharide-initiated polyether polyol is present in an amount of 10 to 45% by weight, based on the total weight of the polyol blend. 
     
     
       3. The polyol blend of  claim 2 , wherein the aromatic polyester polyol is present in an amount of 50 to 85% by weight, based on the total weight of the polyol blend. 
     
     
       4. The polyol blend of  claim 3 , wherein the aromatic polyester polyol and the saccharide-initiated polyether polyol are present in the polyol blend in a weight ratio of 2:1 to 8:1. 
     
     
       5. The polyol blend of  claim 1 , wherein the polyalkylene polyamine is of the general formula: 
       
         
           
           
               
               
           
         
         in which each R is independently hydrogen or a C 1 -C 4  alkyl, each n is independently 0, 1, 2, 3, or 4, and y is an integer having a value of at least 1. 
       
     
     
       6. The polyol blend of  claim 5 , wherein the polyalkylene polyamine comprises triethylenetetramine. 
     
     
       7. The polyol blend of  claim 5 , wherein the polyalkylene polyamine-initiated polyether polyol has an OH number of 150 to 400 mg KOH/g and a functionality of 3.5 to 7.5. 
     
     
       8. The polyol blend of  claim 1 , wherein the aromatic polyester polyol and the polyalkylene polyamine-initiated polyether polyol are present in the polyol blend in a weight ratio of 2:1 to 8:1 and the saccharide-initiated polyether polyol and the polyalkylene polyamine-initiated polyether polyol are present in the polyol blend in a weight ratio of 0.5:1 to 4:1. 
     
     
       9. An isocyanate-reactive composition comprising:
 (1) the polyol blend of  claim 1 ; and 
 (2) a blowing agent composition. 
 
     
     
       10. The isocyanate-reactive composition of  claim 9 , wherein the blowing agent composition comprises:
 (i) a physical blowing agent; and 
 (ii) a carbon dioxide generating chemical blowing agent. 
 
     
     
       11. The isocyanate-reactive composition of  claim 10 , wherein the physical blowing agent comprises a hydrochlorofluoroolefin. 
     
     
       12. The isocyanate-reactive composition of  claim 11 , wherein the hydrochlorofluoroolefin is present in an amount of 10 to 30% by weight, based on the total weight of the isocyanate-reactive composition, and the carbon dioxide generating chemical blowing agent is present in an amount of 1 to 4% by weight, based on the total weight of the isocyanate-reactive composition. 
     
     
       13. The isocyanate-reactive composition of  claim 9 , further comprising:
 (3) a catalyst composition comprising a tertiary amine. 
 
     
     
       14. The isocyanate-reactive composition of  claim 13 , wherein the tertiary amine comprises a morpholine and/or an imidazole. 
     
     
       15. The isocyanate-reactive composition of  claim 13 , wherein the catalyst composition further comprises a trimerization catalyst comprising a quaternary ammonium salt. 
     
     
       16. A process for producing rigid foam, comprising mixing an organic isocyanate with the isocyanate-reactive composition of  claim 9  at an isocyanate index of 90 to 150 to form a reaction mixture. 
     
     
       17. The process of  claim 16 , wherein the reaction mixture is poured into a cavity of a mold of a desired part, wherein the cavity is lined with a facer.